Rolling mill



July 28, 1936. W, Bl SNYDER 2,049,332

ROLLING MILL Filed Dec. 3l, 1932 Inventor: Wil Ham B. Sngder;

by l Hi s Attorneg.

Patented July 28, 1936 'UNITED STATES ROLLING MILL William B. Snyder, Schenectady, N. Y., assignor to General Electric Company, a corporation of New Yori;

Application December 31, 1932, Serial No. 649,695

2 Claims. (Cl. S33-itil.)

My invention relates to rolling mills and has for its object means for automatically indicating acondition of the material after each rolling operation.

Although not limited thereto, my invention has particular application in the rolling of sheet steel in packs, each pack consisting of a plurailty of sheets. In the rolling of the packs, the pack is repeatedly passed through the mill to eiect the gradual reduction in thickness of the sheet. As the pack is rolled down and the thickness of the material decreased the pack itself increases in width and length. Itis an object of my invention to provide an indicating. device for automatically indicating the thickness of the material as a function of the length of the pack so that the operator can obtain a reliable indication of the thickness of the material without shutting down the mill.

In carrying out my invention in one 'form I '20 provide an indicator which may be driven by the mill together with clutching means operated by the passage of the pack through the mill to connect the indicator to the mill each time it enters the mill and to disconnect it as the pack leaves the mill together with means for returning the indicator to a zero position when it is disconnected. The range of movement of the indicator l thus'gives a reliable indication of the length of thepack and hence the thickness of the material.

For a more complete understanding of my invention reference should be had to the accompanying drawing Fig. 1 of' which shows in diagrammatic form a steel mill provided with in- 'dicating means embodying my invention while ,5. (Fig`- 2 is a 'fragmentary view showing'a modified fornio! my'invention.

' Referringto the drawing, while the mill may be of any conventional type for performing arolllng or other operation on material'passed through it,

.1,0 I have shown it as a conventional form of steel mill for the rolling of sheet metal in packs. As shown diagrammatically the mill comprises rolls I Il and II with tables I2 and I3 on opposite sides to convey the material to and from the rolls. The 4,5 material, shown ras a pack I4 of sheet material, may be fed to the rolls from the table I2 and received upon the table I3. After thus being received uponthe table I3 the material is passed back over therolls to the table I2 by elevating the tables about their pivotsupports- I5 and I3 by suitable means (not shown). The packvis conveyed on the tables on suitable endless con-l veyors carried by the tables and' driven'respectively by electric motors Il and I8. When the pack has thus been transferred back to the table I2 the tables are lowered again to the positions shown in the drawing for a repetition oi the rolling operation.

The motors I l and i8 are suitably controlled by a manually operated switch i9 which in turn 5 controls the reversing contactors 28 and 2I to control the starting and stopping of the motors I I and I8 for each direction of rotation. The switch 2| when closed causes the motors vto move the pack from the left to the right., whereas the 10 pack is returned when the switch 20 is closed. Obviously the switch I9 may be operated automatically with the lifting and lowering of the tables to produce a plurality of passes of the material through the rolls, which may-be of course 15 screwed down for each pass to produce a predetermined reduction in the pack. The rolls are driven through a suitable driving motor 25 connected to the lowermost roll II through a-speed reduction gearing 26. 2o

In accordance with my invention I provide an indicating device 2l'which may be connected through a clutch 28 in driving relation with the rolls for the period that the material is passing through the rolls and thus give an indication 2.- of the length of the pack and hence of the thickness oi.' the sheets. As shown, the indicator comprises an index hand 29 which is driven from the motor 25 through a bevel gearing 30, clutch 528,' gearing 3| and an electrical driving connec- 30 each device being provided with a single circuit eld winding supplied from a suitable source of alternating current 34, and a three circuit armaturev winding. The two armature windings are electrically connected together through the con- 40 ,Y ductors 35.

V.Asthus arranged it will be observed that the rotation ofv the motor 25 is continuously repeated by the receiving device 32 which transmits this motion through the reduction gearing 3| to one 45 member of the clutch 28. The movable member of the clutch is normally biased to the left as shown in the drawing to its disengaged position by means vof a pivoted'lever 3l and a spring 38. By means of an operating coil 39 the lever 3l may 50 be pulled over in a counterclockwise direction about its pivot to engage the clutch 28 whereupon the index hand 29 is driven from the motor 25.

In order that the index hand will be driven only while the pack is passing through the rolls l so that its maximum indication will be a measure of the length o! the pack I provide means responsive to the position of the pack for controlling the energization of the coil 39. As shown in Fig. 1 this means comprises a light sensitive control device or photo-electric cell mounted below the table I3 adjacent the rolls and arranged to receive light from a source of light 4I mounted above the table. The photo-electric cell and the light source are so arranged that the beam oflight is interrupted by the pack as it enters the rolls. In other words, the pack I4 as it moves from the table I2 toward the right to the table I3 interrupts the beam of light 42 with its righthand end as this end emerges from the rolls. This interruption of the beam of light renders the photo-electric cell inactive and consequently its output circuit, or the output circuit of a suitable amplifier 43 controlled by it, is deenergized whereupon a relay winding 44 connected in this output circuit is deenergized to allow the switch 45 to close thus closing the circuit from the supply source 34 to the clutch operating coil 39. The clutch is thus moved to establish a connection between the index hand and the driving motor 25 of the mill and thus the index hand is moved over toward the right on the scale 46 as the pack passes through the rolls until the beam of light 42 is again reestablished to the photo-electric cell 40 by movement of the left-hand end of the pack I4 to a position to the right of the beam. The photo-electric cell is thereupon activated again to cause energization of the coil 44 to open the relay switch 45 whereupon the clutch coil 38 is deenergized and the clutch released by the spring 38. The index hand 29 is thereupon returned to its zero position as shown in the drawing by the spring 41 connected to it. Thus the mill operator by observing the maximum travel of the index hand has a reliable indication of the length of the pack, i. e., of the thickness of the sheets of material comprising the pack.

For the purpose of preventing operation of the index hand 29 while the material in the pack I4 f' is being passed to the left over the rolls from the table I3 to the table i2, I provided an interlock switch Eil in the circuit of the operating coil 39, this switch being connected to the contactor 20 so as to be opened when the contactor 20 is closed to return the material to the table I2. Consequently since the switch 50 is opened when this switch is closed the clutch operating coil 38 canbe energized and the clutch will not be enged to drive the index hand at that time.

modied form of my invention shown in ag. 2, a switch arm 53 is provided which is attached to the upper roll 54 of the mill, preferably to the bearing 55 of the upper roll which, it will be understood, is slidably mounted in a vertical direction in suitable guides to permit adjustment of the roll. It will be understood that as the material leaves the mill the upper roll drops down temporarily into engagement with the lower roll and that as the material enters the roll the upper roll is raised to its limit of adjustment. Therefore as the material enters the rolls the upper roll is raised carrying with it the contact arm 53 into engagement with the contacts 5E to close the circuit through them. This switch formed by the contact arm 53 and the contacts 56 is connected in the circuit of the clutch coil 39 in place of the switch 4l. The photo electric cell 40 and associated elements are therefore not used, this modilied system otherwise being as shown in lFig. 1 with the modiiications previously described.

While I have shown a particular embodiment oi'my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A material thickness indicating system for a mill for rolling material wherein the material is repeatedly passed through said mill in a predetermined direction and returned in an opposite direction to the other side of the mill between consecutive passes in said predetermined direction, comprising an indicating device, driving means for the mill, means for connecting said indicating device to said driving means, a switch for controlling said connecting means, a lightresponsive device for controlling said switch, a source of light arranged to throw a beam of light to said light-responsive device across the path of the material as it moves through the mill in said predetermined direction whereby said beam of light is interrupted by the material to cause operation of said switch and thereby connect said indicating device to said driving means, and means biasing said indicating device'to a predetermined position for returning said indicating device to said predetermined position when it is disconnected from said driving means by the passage of the material through the beam of light in said predetermined direction whereby the amount of movement of said indicating device is a measure of the length of the material after each passage through said mill, and means responsive to the movement of the material in the opposite direction for disabling said connecting means.

2. A material thickness indicating system for a mill for rolling packs of sheet material provided with material conveying means for repeatedly passing the pack through the mill in a predetermined direction and returning the pack in the opposite direction to the other side of the mill between consecutive passes in said predetermined direction, comprising an indicating device, a clutch for connecting said indicating device to said mill, operating means for said clutch, a switch for controlling said operating means, means responsive to movement of the pack in said predetermined direction for operating said switch to engagesaid clutch at the beginning oi the passage of the pack through the mill in said predetermined direction and for disengaging said clutch upon the completion of said passage, means for returning said indicating device to a predetermined position when said clutch is disengaged, means for driving the material conveying means, means for reversing said driving means to control the movements of the pack and 6 means responsive to operation of said reversing means for disabling said clutch operating means during return of the pack after each passage in said predetermined direction.

WILLIAM B. SNYDER. 

